In the installation of electrical power distributions systems, it is common practice to run a tap wire from a permenantly-installed main power cable. To accomplish this it is common practice to embrace the cable and the wire in a sleeve and to drive a wedge between the cable and tap wire (inside of the sleeve). This locks the sleeve, cables, and wedge together to make a strong physical and electrical connection. For a proper installation, it is not only necessary to drive the wedge into the sleeve with considerable force, but also to do so with a selected force commenserate with the size of the sleeve and wedge that is used, thus, obtaining a standard, reproducible force between the elements. For this purpose, it is usual practice to use a power tool of the type that is shown and described in the Wahl U.S. Pat. No. 3,292,363, which makes use of a explosive cartridge to generate the force between the sleeve and the wedge. Among other features of such a power tool, it is important that the operation be carried out very quickly and under the greatest safety conditions, because the worker in many instances is working high above the ground with high voltage power lines. The prior art devices, however, have been slow to operate, because, in order to release the trapped pressure gases resulting from the explosion, it is necessary to carry out a time-consuming unscrewing operation at the back of the chamber. Furthermore, some of the devices are unsafe, because there is nothing to prevent premature actuation of the explosive device before that the obturating mechanism is fully secured. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a power tool in which safety is promoted by rendering the the firing mechanism inoperative until the obturating mechanism has been fully secured.
Another object of this invention is the provision of a power tool for use in making electrical connections, wherein the pressure gas in the chamber is quickly and easily released after the explosion.
A further object of the present invention is the provision of a power tool in which the cycle of loading, firing, and unloading takes place very quickly.
It is another object of the instant invention to provide a tool using an explosive cartridge in which the cartridge is inoperative until the tool is in position for firing.
A still further object of the invention is the provision of a power tool in which the complete closing and sealing of the obturating mechanism is made clearly evident to the operator.
It is still a further object of the invention to provide a tool for use in assembling an electrical connector which is simple in construction, which is inexpensive to manufacture, and which is cable of a long life of useful service with a minimum of maintenance.
It is a still further object of the present invention to provide a power tool for assembling an electrical connector in which the cartridge is inoperative until the tool has been properly located on the connector for firing.
Another object of the invention is the provision of a power tool using an explosive cartridge in which the cartridge is rendered firable and the firing mechanisms is rendered operatable by the placement of the tool on the article that is to be connected.